The local HTTP server approach (fetch to 127.0.0.1) doesn't work in the Wails webview. Simplify: use window.open() to launch OIDC in the real browser. After authentication, the callback page at the server shows the token. User copies and pastes into the Token tab. Also fix: SetSize before app.Run() crashes with nil pointer — use WebviewWindowOptions width/height directly from restored state.